Posterior Epidural Space Research Articles

Hirayama Disease: Neutral and Flexion Magnetic Resonance Imaging Manifestations and Single Tertiary Care Center Analysis on 3T Scanner.

Hirayama disease (HD) is a rare benign type of cervical cord myelopathy occurring commonly in young males as unilateral or bilateral asymmetrical amyotrophy of the hand and forearm muscles in C8-T1 distribution. Magnetic resonance imaging (MRI) is the best technique for the evaluation and imaging of this entity. This is a retrospective review of cervical magnetic resonance images of patients that were taken for clinically suspected and diagnosed HD on 3T MRI in postcontrast neutral and flexion (30°-40°) positions from July 2019 to January 2024 at Shri Ram Murti Smarak Institute of Medical Sciences, Bareilly. Fourteen patients included in the study were males less than 34 years of age. MRI findings of cord atrophy in the lower cervical region/cervico-dorsal junction, abnormal cervical curvature, loss of attachment of the dorsal dural sac and subjacent laminae with anterior displacement, and a prominent intense enhancing posterior epidural space were observed in all 14 patients. The minimum anteroposterior cord diameters in the neutral and flexion positions were 2.9 and 2.8 mm, respectively (mean thickness of laminodural space on flexion - 5.2 mm). Other MRI findings showed variable representations. Flexion-position MRI has emerged as the gold standard for establishing and validating the diagnosis of HD in clinically suspected cases and should be an essential part of the protocol for the screening of clinically suspected cases of HD to aid in early treatment and therapeutic intervention. Complimentary newer sequences such as the Three-dimensional (3D)-Constructive interference in Steady State (CISS)/Fast Imaging Employing Steady-state Acquisition Cycled Phases (FIESTA-C) may reinforce better appreciation of epidural flow voids.

Correlation between epidural space depth measured with ultrasound and MRI compared to clinical loss of resistance when performing lumbar epidural steroid injection

BackgroundThis prospective study assessed the accuracy of MRI and ultrasound (US) measurements as a preprocedural assessment tool for predicting clinical loss of resistance depth (CLORD) during fluoroscopy-guided lumbar epidural steroid...

Characteristics of Hirayama Disease in Young South Korean Soldiers.

The purpose of this study was to describe the clinical presentation and features in electrodiagnostic and imaging investigations of young South Korean males diagnosed with Hirayama disease (HD). We reviewed the electronic medical records of South Korean enlisted soldiers who were diagnosed with HD and discharged from military service during 2011-2021. We investigated the clinical characteristics and results of electrodiagnostic and magnetic resonance imaging (MRI) investigations. We analyzed laterality and identified the involved muscles using needle electromyography (EMG). Loss of lordosis, localized cervical cord atrophy, loss of attachment between the posterior dura and subjacent lamina, asymmetric flattening of the cord, crescent-shaped mass in the posterior epidural space, and noncompressive intramedullary T2-weighted high signal intensity were investigated using neutral- or flexion-position MRI. Forty-two male patients aged 20.2±0.8 years (mean±standard deviation) were identified. All patients complained of hand weakness, and 10 complained of hand tremor (23.8%). Four patients (9.5%) had symptoms in both upper limbs, and five (11.9%) had sensory disturbances. Needle EMG revealed that muscles in the C7-T1 myotome were commonly involved, and C5-C6 involvement of the deltoid (10.5%) and biceps brachii (12.5%) was also observed. In cervical MRI, localized cord atrophy (90.0%) was the most characteristic finding, and cord atrophy was most severe at the C5-C6 level (58.3%). This is the first description of a large number of patients with HD in South Korea. The clinical presentation and features found in electrodiagnostic and imaging investigations will improve the understanding of HD in the young South Korean male population.

Huge extradural multilevel lumbar abscess

Extensive spinal epidural abscesses (ESEAs), occupying three or more spinal regions, are rare forms of vertebral infection. Multilevel laminectomy in these cases is controversial because of the risk of vertebral instability. We report the case of a 47-year-old patient known with ureterohydronephrosis 2nd degree, admitted for severe vertebral pain (VAS 8/10) from 2 months, paraparesis (ASIA 1/5 left, 4/5 right, retention of urine and faeces) from three days. The analysis discovered Diabetes Mellitus type 2, and high levels of inflammatory tests. CT and MRI of the vertebral area with contrast revealed dorsal compression of the spinal cord and cauda equina by an epidural abscess extending from L1-L5, bilateral in the soft adjacent paravertebral tissues especially psoas muscles but sparing the intervertebral discs. Surgical treatment: alternate fenestrations L1-L5, more important on the left side. By this technique, we removed the fluid pus and also granulomatous pus from posterior epidural space L1-L5, bilateral medial foramina, interspinous and supraspinous space, and psoas muscles. The identified germ was Staphylococcus aureus ++++. Postoperatively, we used a continuous drainage washing system with Vancomicyne and diluted Betadine—a course of six-week Vancomycin 2 grams/day iv. The drainage system was blocked after 24 hours and we had to remove it and all the wires of the suture. We had to dress up every day for the surgical field and wash deep inside the field with diluted betadine for 3 weeks till the surgical field was completely cured. After 3 months postoperatively the patient was cured radiologically and clinically. Follow up 18 months. Conclusion: alternate fenestration has the advantages of removing liquid and granulomatous pus in the epidural posterior area and preserving the spine stability.

Cervical Spine Magnetic Resonance Imaging Findings in Hirayama Disease.

Background Hirayama disease is an uncommon type of cervical cord myelopathy seen typically in young males due to trauma from flexion movements. This study aims to assess the clinical presentations and classify the extent of various cervical spine MRI findings for the local population. Methodology A retrospective study of 13 patients diagnosed with Hirayama disease oncervical MRI was performed from January 2017 to December 2022 at Dr. D. Y. Patil Medical College, Hospital and Research Center, Pune. Results Of the 13 patients, 12 (92%) were male, and one (8%) was female. Nine (69%) patients were in the 16-25-year age group, two (15%) were in the 26-35-year age group, and one (8%) each was in the 6-15-year and 66-75-year age groups. Upper limb weakness was the most common clinical symptom seen in 12 (92%) patients, followed by distal muscle atrophy in seven (54%) patients. Tremors in the hand were a rare symptom seen in two patients. Claw hand was an atypical symptom seen in one patient. On cervical MRI, all patients showed excessive forward shifting of the posterior dura on flexion, with resultant cord compression due to tightness of the dural sac. One (8%) patient had no signs of myelopathy, while 12 (92%) patients had developed chronic myelomalacia and showed abnormal cord hyperintensity and atrophy in the lower cervical cord. All 13 (100%) patients showed increased laminodural space on flexion; the mean thickness was 4.08 mm, with the minimum and maximum thickness being 2.4 mm and 6.7 mm, respectively. Classifying by length of the anterior bulging dura, one (8%) patient showed involvement of less than two vertebral body segments, eight (62%) patients showed involvement of two to four vertebral body segments, and four (30%) patients showed involvement of more than four vertebral body segments. Crescent-shaped post-contrast enhancement on flexion was seen in all eight (100%) patients who underwent a contrast study. Prominent epidural flow voids on flexion were seen in six (46%) patients. Conclusions Hirayama disease is an uncommon type of cervical myelopathy seen typically in juvenile males. The occult onset of distal upper limb weakness and atrophy during puberty, typical MRI features of lower cervical cord atrophy, and the presence of a crescent-shaped enhancing mass in the posterior epidural space are pathognomonic of the condition. A few atypical cases can also occur. Early diagnosis and treatment are crucial to avoiding serious dysfunction.

ID: 220962 Inpatient Spinal Cord Stimulation Trial in Patient With Metastatic Colon Cancer Hospitalized for Pain Control

A 55-year-old female with metastatic colon cancer with a soft tissue mass at S1 extending into the vertebral body and posterior epidural space and neuroforamina at L5-S1 was hospitalized for severe lumbar back and bilateral radicular pain. She was initially managed inpatient with escalating dosing of opioid pain medication with minimal improvement of her symptoms. She was unable to ambulate more than 2-3 steps secondary to weakness and pain.

ID: 204152 Single Versus Dual Lead Spinal Cord Stimulation Trials

Spinal cord stimulation (SCS) has been used to treat chronic low back pain (LBP) since it was first proposed by Shealy et al. (1). SCS required placing electrodes in the posterior epidural space near the dorsal columns with electrical stimulation delivered at low-frequency 30-60 Hz (LFSCS) with concordant paresthesia elicited in the areas of pain (2). 10 kHz high-frequency spinal cord stimulation (HF10) was introduced and required no paresthesia mapping and used standardized reproducible epidural lead placement. Several studies have shown the clinical superiority of HF10 over LFSCS, including the two SENZA-RCTs(4,5). Since no paresthesia mapping is needed, we wanted to see if single lead trial would be comparable to standard dual lead trial.

Role of Dynamic Magnetic Resonance Imaging in Hirayama Disease, a Rare Motor Neuron Disease.

Introduction Hirayama disease (HD) is a benign self-limiting motor neuron disease, most commonly occurring in young males. The disease has an insidious onset that affects T1, C8, and C7 myotomes. HD is more common in Japan and Asian countries, and rare in the western population. Magnetic resonance imaging (MRI) is the best technique for the diagnosis of this entity. Early diagnosis is important as the patients can be advised to limit neck flexion movements to arrest the progression of the disease. Any clinically suspected case of Hirayama disease should undergo flexion MRI as conventional neutral MRI may miss findings in a few cases. The purpose of the present study is to evaluate the usefulness of flexion MR imaging and laminodural space (LDS) measurement in young patients with clinical and electroneuromyography (ENMG) definite Hirayama disease. Materials and methods This is a retrospective observational studyof 15patients with clinical and ENMG definite Hirayama disease who were referred to the Department of Radiology. These patients underwent MRI of cervical spine in neutral position and with neck flexion of 30°-40°. In neutral MRI, atrophy and T2-weighted hyperintensities in the cord were noted. In flexion MRI, the maximum forward shifting of the posterior dural sac, also known asthe LDS, was noted along with other parameters. Observation The mean age of the study population was21 ± 3.36 years. Out of 15 patients, 14 were males and one was female; 14 patients (93.3%) had an involvement of unilateral upper extremity while one patient (6.6%) had asymmetric bilateral involvement. Straightening of cervical spinal curvature and cord atrophy was seen in 14 (93.3%) and 12 (80%) patients, respectively, on neutral position MRI.Intramedullary cervical cord T2-weighted hyperintensities were noted in eight patients (53.3%). Loss of the dural attachment and forward shifting of the posterior dural sac with prominent posterior epidural space was noted in all patients (100%). At the maximum forward shift of cord, the LDSranged from 3.1 to 7.0 mm, with a mean of 5.38 ± 1.13 mm.Epidural flow voids were noted in 86.6%of cases. Conclusion Flexion MRI plays a very important role in confirming the diagnosis of Hirayama disease in clinically suspected cases.Anterior displacement of posterior dura matter and widening of LDS is notedin all cases in our study. Even though findings like cord atrophy and T2 hyperintensities are seen in conventional neutral MRI, these findings are not seen in all cases. So flexion MRI increases diagnostic confidence by showing increased LDS, which is a characteristic finding in Hirayama disease.

Fluoroscopy-assisted epidural catheter placement: the effect of dye distribution in preoperative epidurograms on postoperative analgesia

BackgroundPostoperative epidural analgesia provides superior postoperative analgesia at rest and with activity, compared with systemic opioids. However, the impact of postoperative epidural analgesia on postoperative morbidity and/or mortality remains controversial, because of the sub-optimal reliability of epidural catheters that are placed preoperatively and used for postoperative pain control. The present study used the technique of lumbar epidurography. The study aims to better understand the possible correlation between the fluoroscopic characteristics of epidural catheters following injection of contrast medium and the postoperative functional characteristics regarding analgesia. In this single-arm clinical trial, 70 patients, aged 50 to 75 years old, underwent surgical urological procedures, involving incisions up to T8 dermatome, under combined general and epidural anesthesia. At the L2-L3 level, the epidural space was reached using the loss of resistance technique before general anesthesia was induced. The catheters were threaded upwards for 4–6 cm. Preoperative epidurograms were then done by injecting a 3-ml contrast medium OmnipaqueTM (240 mg I/ml) in the epidural catheters. The epidurograms were investigated for the location of the catheter tip in relation to the vertebral body, the extent of dye spread, laterality of dye spread (midline, right, or left), and the presence or absence of dye spread anterior to the spinal cord on the lateral image. The patients were followed postoperatively while epidural analgesia was infused.ResultsBoth the postoperative epidural infusion and postoperative visual analog scale (VAS) scores were lower when catheter tips ended at L1 than when they ended at L2. As the contrast’s vertical spread increases in preoperative epidurograms, the analgesic infusion rate and VAS score decrease, and the number of dermatomes insensitive to cold increases. Epidurographically right-sided catheters showed more dermatomes deficient to cold sensations on the right side, compared with mid-line and left-sided catheters. Restriction of contrast to the posterior epidural space was associated with lower VAS scores and wider anesthesia to cold.ConclusionsThe use of epidurography to study epidural catheters may have the potential advantage of predicting the functionality of catheters and improving the reliability of postoperative epidural analgesia.

Hirayama disease: neutral and flexion magnetic resonance imaging and utility of inter-segmental angle of flexion.

Hirayama disease (HD) is a rare disease that was commonly mis-diagnosed in the past. The importance of neutral and flexion magnetic resonance imaging (MRI) in its accurate diagnosis has been emphasized along with utility of the inter-segmental angle of flexion. Aim of the study was to observe MRI findings of HD in neutral and flexion position and measure the inter-segmental angle of flexion. Cervical MR images of 17 patients of suspected HD were evaluated retrospectively for loss of attachment (LOA) of posterior dura, lower cervical cord atrophy, T2 hyperintensity, loss of cervical lordosis, enhancement of posterior epidural venous plexus, and inter-segmental angle of flexion on neutral and flexion MRIs. Flexion MRI showed LOA of posterior dura (most commonly and maximum at C6 vertebral level) and intense enhancement in posterior epidural space in almost all patients. The mean inter-segmental angle of flexion at C5-C6 was 9.2°, and at C6-C7 it was 6°. Neutral MRI revealed LOA in 64.7%, lower cervical cord atrophy in all patients, T2 hyperintensity in the lower cervical cord in 35.2% of patients, and loss of cervical lordosis in 58.8% of patients. Flexion MRI is the gold standard for diagnosis of HD; however, certain imaging attributes, i.e. loss of attachment of posterior dura, asymmetrical lower cervical cord atrophy, T2 hyperintensity, and loss of cervical lordosis, can be seen on neutral MRI as well, which subsequently prompts the radiologist to include flexion MRI for confirmation. The inter-segmental angle of flexion is increased in patients with HD, which plays a role in planning timely surgical intervention.

GRANULOCYTIC SARCOMA OF THE CNS AS A CAUSE OF MEDULLARY COMPRESSION: A CASE REPORT

A 24-year-old man, previously healthy, presented to the hospital emergency in February 2021, complaining of pain in the back region radiating to the flanks and hips for 12 days. He had previously sought care on three occasions, without relief with anti-inflammatory drugs. On admission, his physical examination was normal, and laboratory tests showed 23900 leukocytosis and 70% blasts, no anemia or thrombocytopenia, normal renal and liver function tests, and negative serologies. Chest radiography and ultrasound of the abdomen plus urinary tract showed no particularities. Immunophenotyping was requested, which diagnosed maturation acute myeloid leukemia; the patient was hospitalized for therapy. He still complained of intermittent pain crises in the lumbar region, evolving with bladder dysfunction, weakness, and paresthesia in both lower limbs. Upon starting protocol with Cytarabine + Daunorubicin on the fourth day of hospitalization, the man evolved with proprioceptive loss and paraplegia of the lower limbs. Urgent magnetic resonance was requested, showing an expansive formation in the posterior epidural space at the level of T9-T11, suggestive of granulocytic sarcoma. Lesion biopsy was not performed. A course of dexamethasone was carried out and a response to chemotherapy was observed; the patient had a partial return of strength in both lower limbs and completed the systemic treatment. Acute myeloid leukemia (AML) is the most prevalent acute leukemia in adults, representing about 1% of all neoplasms, 10% of which are of the subtype called AML with maturation. This is the subtype most associated with granulocytic sarcoma, also called chloroma. Granulocytic sarcoma is a solid tumor of granulocyte precursor cells located in various extramedullary sites, which can cause a copious constellation of symptoms. In this case, MRI showed a highly suspicious lesion for infiltrative chloroma in the CNS, causing a medullary compression syndrome with serious clinical repercussions. In other tissues, local management of the tumor can be performed with surgical resection or radiotherapy, which were unfeasible therapeutic options for the case presented. Although rare, granulocytic sarcoma should be considered a differential diagnosis in patients with acute leukemia, who present with compressive symptoms. In some cases, it may represent a hematological urgency, even before the primary neoplasm diagnosis, and its correct management is essential in such situations.

Correlation of skin epidural distance and posterior epidural space depth with age, weight, height, BMI, abdominal girth and position of the patient: A prospective randomised study

Lumbar epidural block is a commonly used procedure for providing anaesthesia, post-operative analgesia in all groups of patients irrespective of age, sex, weight and height of the patients. The knowledge of posterior space is important in view of the fact that this is the space where drugs for epidural anaesthesia/ analgesia are used. The knowledge of variability of this space with physical parameters of the patient, help us in reducing the incidence of total spinal anaesthesia.Two hundred adult patients in the age group of 20-60 years requiring subarachnoid block were chosen for the study. Using 22G Quincke spinal needle, epidural space was identified and skin epidural distance was measured. Proceeding the spinal needle further, causes needle to lie in subarachnoid space. The skin subarachnoid distance was measured. The difference between skin-subarachnoid distance and skin epidural distance denoted the posterior epidural space width. Its correlation with physical parameters was studied.Mean skin epidural distance was 4.30 ±0.57 in lateral position and 4.05 ± 0.57 in sitting position, the difference being statistically significant. (P= 0.002). There was positive correlation between skin epidural distance with weight, BMI and abdominal girth of the patient. Mean posterior epidural space depth was 0.468+14 cm in lateral position and 0.459+0.14 cm in sitting position, the difference being statistically insignificant. There was a positive correlation between posterior epidural space depth and height of the patient.The skin epidural distance varies with weight, BMI, abdominal girth and position of the patient. The posterior epidural space depth varies with the height of the patients.

Successful Nonoperative Management of Acute Spontaneous Idiopathic Spinal Epidural Hematoma Presenting as Cauda Equina Syndrome

Spontaneous spinal epidural hematoma (SSEH) is a rare neurosurgical condition with an estimated incidence of 0.1 in 1,00,000 population.[1] It has been most commonly described in the older age group in the 4th or 5th decade of life and most commonly found in the dorsal or dorsolumbar region.[2] It can present with a variety of clinical symptomatology, depending upon the site and extent of hematoma, usually in the form of acute cervical or back pain along with rapid onset of neurological deficits, often within first 12 hours of ictus and often requiring urgent neurosurgical intervention. However, its first manifestation as cauda equina syndrome is rare. Emergent surgical evacuation has remained the gold standard of treatment,[3] and only a handful of cases reported successful recovery with conservative management, and that too primarily in patients with a diffuse SSEH associated with blood dyscrasias or coagulopathy.[4] We describe a case of a 25-year-old healthy male, who presented with history of sudden onset severe back pain, followed by rapidly progressive paraplegia and cauda equina syndrome, four days after lifting heavy weight. He had to be catheterized for urinary retention. He presented to our clinic 1 month after the onset of symptoms, and by then, partial recovery of sensory, motor and autonomic deficits had already ensued. The coagulation profile was within normal parameters. His MRI performed immediately after the onset of symptoms demonstrated a T2-hyperintense lesion in posterior epidural space at L2-3 vertebral level, which was suggestive of a focal epidural hematoma with significant secondary canal compromise ( [Fig. 1 A,B] ). There was no evidence of associated flow-voids to suggest an associated vascular malformation. Due to delayed referral of patient and subacute stage of epidural hematoma with partial spontaneous recovery at the time of presentation, decision was taken to manage it conservatively with symptomatic pain management and limb physiotherapy. He recovered nearly completely over the next 1 month, and he was able to walk with minimal support and regained bladder function (American Spinal Injury Association [ASIA] D). His interval MRI demonstrated complete resolution of epidural hematoma ( [Fig. 2 A,B] ).

Dural sac shrinkage signs on magnetic resonance imaging at the thoracic level in spontaneous intracranial hypotension-its clinical significance.

Spontaneous intracranial hypotension (SIH) is secondary to a cerebrospinal fluid leak at the spinal level without obvious causative events. Several signs on brain and cervical spine magnetic resonance (MR) imaging (MRI) have been associated with SIH but can be equivocal or negative. This retrospective study sought to identify characteristic SIH signs on thoracic spinal MRI. Cranial and spinal MR images of 27 consecutive patients with classic SIH symptoms, who eventually received epidural autologous blood patches (EBPs), were analyzed. The most prevalent findings on T2-weighted MRI at the thoracic level were anterior shift of the spinal cord (96.3%) and dorsal dura mater (81.5%), probably caused by dural sac shrinkage. These dural sac shrinkage signs (DSSS) were frequently accompanied by cerebrospinal fluid collection in the posterior epidural space (77.8%) and a prominent epidural venous plexus (77.8%). These findings disappeared in all six patients who underwent post-EBP spinal MRI. Dural enhancement and brain sagging were minimum or absent on the cranial MR images of seven patients, although DSSS were obvious in these seven patients. For 23 patients with SIH and 28 healthy volunteers, a diagnostic test using thoracic MRI was performed by 13 experts to validate the usefulness of DSSS. The median sensitivity, specificity, positive-predictive value, negative-predictive value, and accuracy of the DSSS were high (range, 0.913-0.931). Detection of DSSS on thoracic MRI facilitates an SIH diagnosis without the use of invasive imaging modalities. The DSSS were positive even in patients in whom classic cranial MRI signs for SIH were equivocal or minimal.

A common yet undescribed MRI finding in newborns: posterior epidural space edema of the cervical and upper thoracic spine

Posterior spinal epidural space (PSES) is a fat-containing space. We noted numerous spinal MRIs demonstrating T2-hyperintense thickening of the cervical/thoracic PSES in early newborns, resembling epidural edema. Our aim is to describe the appearance/frequency of this finding and explore any associations with delivery. Retrospectively, 202 spinal/cranial MRIs, belonging to newborns within the first 2 weeks of life, were evaluated using sagittal fat-suppressed T2, T1-FLAIR, and STIR. Exclusion criteria were motion, incomplete spine imaging, lack of sagittal T2/STIR, and inadequate clinical data. Ninety-three patients were included in the final analysis. We reviewed all cases for T2 hyperintense thickened PSES and, if present, accompanying abnormal T1 signal. The spinal canal and PSES thickness were measured. Clinical and demographic data were collected. Follow-up exams were evaluated, if available. Cases with thickened PSES and without were compared. T2-hyperintense thickened PSES was present in 60/93 (64.5%). Mean PSES thickness was 2.3 mm (0.7-4.6). The mean PSES thickness/spinal canal diameter ratio was 0.2 (0.1-0.5). No cord compression was identified. One had a hyperintense T1 PSES signal, compatible with epidural hemorrhage. No difference was found between those with thickened PSES and without, regarding sex, gestational age, birth weight, birth method, difficult delivery, fetal position, or neurologic status (p>0.05). Follow-up imaging was available in 10, with complete resolution of T2 hyperintense PSES thickening. T2 hyperintense PSES thickening is common in imaged newborns and reversible at follow-up. No significant neurologic outcomes were found related to its presence; thus, follow-up does not appear necessary.

Epidural space "ballooning" during local anaesthetic injection in infants and children: An ultrasound observational study.

Infants and children require a larger dose of a local anaesthetic (LA) to establish epidural analgesia than adults, but the reason for this remains unclear. We hypothesised that prominent ventro-dorsal expansion of the epidural space limits cranio-caudal spread of LA in infants. Accordingly, we studied the dimensions of the epidural space with real-time ultrasound (US) before and after epidural injection. Ninety-six infants and children aged 0-12years who underwent abdominal surgery under combined epidural and general anaesthesia were examined in this prospective observational study. Using a micro-convex probe, US recordings of the posterior epidural space were performed while a LA (0.5mlkg-1 ) was infused at 0.54mls-1 . The width in the ventro-dorsal dimension (VDD) of the posterior epidural space before and after injection was recorded; the change in VDD was defined as "ballooning". Correlations between "ballooning" and patient age, body mass index, and volume and rate of LA administration were analysed. "Ballooning" correlated positively but weakly with age (R2 =0.25; p<.001) and the infused LA volume (R2 =0.32; p<.001). The "magnitude of ballooning" ("ballooning" per ml of injected LA) correlated negatively but weakly with age (R2 =0.27; p<.001). "Magnitude of ballooning" of the epidural space become inconspicuous with growing during epidural injection. This effect may slow the cranio-caudal spread of LA and explain partially why larger volumes of LA are required to effect a block in children.

Transverse plane ultrasound-guided caudal epidural injections: sonographic anatomy and stepwise technique.

The present study aims to provide a step-by-step procedural and anatomical familiarization guide for transverse plane ultrasound (US)-guided caudal epidural (CE) injection. The study cohort consisted of 23 chronic low back pain patients (23-67years old) previously unresponsive to conservative management. A transverse plane US-guided CE injection was performed, with each procedure step documenting and emphasizing sonographic anatomy. Several Thiel's method fixed cadaveric specimen dissections were also performed to demonstrate relevant CE injection-related anatomy. The sacral hiatus location can be estimated by visually forming an equilateral triangle between the posterior superior iliac spines and the sacral apex (trigonum sacrale). Follow-up palpation locates the sacral cornua, guiding transducer placement visualizing over the paired cornua 'bull frog's eye's appearance, with the epidural space visualized as a hypoechoic line, between the eyes. Then, 2-3ml of 1% lidocaine is injected subcutaneously at the mid-point between the sacral cornua and superficial to the posterior sacrococcygeal ligament (SCL). Although keeping the cornua, superficial posterior SCL and epidural space in view, the needle is slowly advanced to the epidural space at around a 20 degree cephalad angle till the tip becomes visible. Expansion of the epidural space is monitored under the transverse sacral ligament as the injectant is slowly introduced. The present study demonstrated the anatomical landmarks necessary for the transverse ultrasound caudal epidural technique and that the cornua, superficial posterior SCL, CE space, and other relevant sacral hiatal anatomy are well visualized with this technique.

The lumbar erector spinae plane block: a cadaveric study.

The aim of this cadaveric study was to investigate the erector spinae plane block (ESPB) in lumbar region and to elucidate the possible mechanisms of action of these injections in lumbar radicular pain by means of detecting expected dye dispersion to the neural structures. Ultrasound-guided lumbar ESPB was performed in three formaldehyde-embalmed human cadavers. For this purpose, a 10 mL of methylene blue was injected into the fascial space between the L4 transverse process and the erector spinae muscles. T hen, the cadavers were dissected, the cephalocaudal and lateral spread of the dye was examined, and the involvement of the dorsal rami, dorsal root ganglia and ventral rami were analyzed. The distribution into the epidural space was also evaluated. The involvement of the dorsal rami was found to extend up to the T12 level and down to the L5 spinal nerves. Although dye dispersion was detected on the dorsal root ganglion in all specimens, it was found to be limited to one or two levels, unlike the dorsal rami. In half of the specimens, distribution to the ventral ramus and posterior epidural space was observed.

Correlation between paravertebral spread of injectate and clinical efficacy in lumbar transforaminal block

The potential paravertebral space includes spinal nerves, dorsal rami, rami communicants, and sympathetic chains. This study evaluated correlations between paravertebral spread of injectate and clinical efficacy in lumbar transforaminal block. We retrospectively analysed the data of 88 patients who received transforaminal blocks for lumbar radicular pain. We categorized patients into two groups: patients with ≥ 50% pain reduction on a numeric rating scale at 30 min following a block (responder group), and patients with < 50% pain reduction (non-responder group). Paravertebral spread of injectate was graded as limited to the anterior, middle, and posterior 1/3 of the anterolateral aspect of vertebral bodies; spread between the posterolateral margins of bodies and the posterior epidural space was considered no spread. Clinical and fluoroscopic data, perfusion index, temperature, and cold sensation were compared between the groups. Among 54 patients analysed, 26 (48.1%) experienced ≥ 50% and 28 (51.9%) < 50% pain reduction. Paravertebral spread occurred in 33 (61.1%) patients; 19 (57.6%) responders and 14 (42.4%) non-responders. On analysis, paravertebral spread, epidural spread patterns, perfusion index change ratios, temperature changes, and cold sensation changes showed no differences between responder and non-responder groups. Paravertebral spread occurred in 61.1%, with no correlation with the clinical efficacy of lumbar transforaminal block.

THE UNEXPECTED WEAKNESS: A CASE REPORT OF SPONTANEOUS SPINAL EPIDURAL HEMATOMA

Spontaneous spinal epidural hematoma is an uncommon cause of acute spinal cord compression. It is a neurologic emergency; urgent imaging and surgical intervention prevent permanent neurologic sequelae. Here, we present the case of a 71-year-old female known to have diabetes mellitus, hypertension, and ischemic heart disease on treatment. She presented to the emergency department with sudden onset of upper back pain with chest discomfort and bilateral lower limb weakness with numbness, which was waxing and waning for 4–6 h. On examination, there were no pulse or blood pressure deficits bilaterally and neurologically power that was 3/5 in both lower limbs with decreased tone and reflexes. In view of possible myeloradiculopathy, a magnetic resonance imaging whole spine was done which showed a lesion in the posterior epidural space, suggestive of hematoma, causing compression of the posterior thecal sac. The final diagnosis was spontaneous C7-T2 epidural hematoma secondary to antiplatelet therapy.